Clarke has been a close colleague of Mary Matalin since the Reagan administration. Clarke often filled in for Matalin on the show Equal Time during its run on CNBC in the 1990s. Clarke is the author of Lipstick on a Pig: Winning In the No-Spin Era by Someone Who Knows the Game (2006, ISBN 0-7432-7116-5), a book about tackling 21st century information challenges. Clarke appeared on the February 7, 2006, episode of The Daily Show to promote it.